1. Field of the Invention
This invention relates to a recording apparatus for use in a copying machine, a printer, a facsimile machine, and similar machines.
2. Description of Related Art
A conventionally known an image forming apparatus is disclosed in U.S. Patent No. 3,689,935 which uses an electrode having plural opening portions (hereinafter referred to as "apertures") formed therein. In this image forming apparatus, a voltage is applied to the electrode on the basis of an image data to control the passage of toner particles through the apertures, and an image (toner image) is formed on a supporter by means of the passed toner particles.
This image forming apparatus includes an aperture electrode member comprising an insulating flat plate, a reference electrode having a continuous body formed on one surface of the flat plate, plural control electrodes which are insulated from one another and formed on the other surface of the flat plate, and at least one array (row) of apertures each of which is formed in correspondence with a control electrode so as to penetrate through the flat plate, the reference electrode and the control electrode.
The image forming apparatus further includes means for selectively applying a potential across the reference electrode and each of the control electrodes, means for supplying charged toner particles so that the flow of the toner particles passed through the apertures is modulated on the basis of the applied potential, and means for positioning the supporter in a particle-flow passage so that the supporter and the aperture electrode member are relatively movable.
In the conventional recording apparatus as described above, the toner which has passed through the opening portions of the toner flow control means does not entirely fly toward a back electrode and a part of the toner is attached to the surface of the control electrodes. The attachment of the toner to the control electrodes disturbs the smooth flight of the toner passing through the opening portions toward the back electrode. In addition, there occurs a problem that the opening portions become clogged with toner.
Further, the toner is attached to the reference electrode side of the aperture electrode member. The attachment of the toner to the reference electrode prevents the toner from properly passing through the opening portions and it causes fog. It finally causes a problem that the opening portions are clogged with the toner.